https://school.programmers.co.kr/learn/courses/30/lessons/150369

1) 코드
def solution(cap, n, deliveries, pickups):
answer = 0
have_to_deli = 0
have_to_pick = 0
for i in range(n-1, -1, -1):
have_to_deli += deliveries[i]
have_to_pick += pickups[i]
while have_to_deli > 0 or have_to_pick > 0:
have_to_deli -= cap
have_to_pick -= cap
answer += ((i+1)*2)
return answer
2) 해설